rest day vs working day

rest day

noun
  • A day spent resting from work or any other activity. 

working day

noun
  • Any of those days of a week on which work is done, officially Monday to Friday in many countries (even though many people work on weekends). 

  • The part of a day in which work is done; the number of hours one must work per day for a specified wage. 

How often have the words rest day and working day occurred in a corpus of books? (source: Google Ngram Viewer )